What does "change" "repair" or "remove" mean in the blender installer?
Sounds like you are using a Windows installer. If that is so, Change, Repair, Remove are the options the installer is giving you. Remove would be un-installation, Repair would be like a re-installation. It should be noted that there is no reason to install Blender on your system, and in fact it is desirable not to. Instead download the compressed archive of Blender for your OS and you can drop the program into your root project directory. This way you can keep whatever version of Blender you are using for each project along with addons/settings on a per project basis and it will be fully portable to other computers. Helps ensure you maintain project compatibility and prevents you from ending up with a dozen Blender installs on your system as each version comes out. Especially true if you ever use developer builds or branches.